In recent years, an optical coherence tomographic imaging method and an optical coherence tomographic imaging apparatus, to which a low coherence interferometer technology or a white light interferometer technology is applied, are in actual use. In particular, an optical tomographic imaging apparatus (optical interferometer apparatus) that performs optical coherence tomography (OCT) utilizing interference phenomenon of multi-wavelength light may obtain a tomogram of a sample with high resolution. Therefore, in the ophthalmological field, the optical tomographic imaging apparatus is becoming an indispensable apparatus for obtaining a tomogram of a fundus or a retina. In addition to the ophthalmological application, the optical tomographic imaging apparatus has also been used for tomographic observation of skin, tomography scan of a digestive and cardiovascular wall with an endoscope or a catheter constituted of the apparatus, or the like. Hereinafter, the optical tomographic imaging apparatus is referred to as an OCT apparatus.
In recent years, the Fourier domain optical coherence tomography (OCT) technology has developed, and, as a result, a period required for the imaging has significantly decreased compared with the conventional time domain optical coherence tomography (OCT). However, if an object such as a human eye is always moving, imaging conditions such as a position of focus and a position of a range of imaging change, resulting in problems such as a decrease in contrast and a frame out of the imaging range. It is thus necessary to obtain an image containing an area of interest as well as a peripheral area thereof for preventing the frame out and comparing the area of interest with the peripheral area thereof.
Japanese Patent Application Laid-Open No. 2009-042197 discloses a method of providing control for increasing an intensity of a signal for constructing an image if the intensity of the signal is less than a predetermined threshold value.